Problems · Battery
Is it bad to leave my laptop plugged in all the time?
You cannot overcharge a modern laptop: it stops drawing charge at full and runs from the mains. The old warning is genuinely obsolete. What does age a lithium battery is being held at a high state of charge, especially while warm, for months on end.
So the practical answer is a compromise the makers themselves now build in. If the machine mostly lives on a desk, turn on the charge limit in its settings and let it sit around 60 to 80 percent instead of 100.
First, notice when it happens
The causes, ranked
1. The overcharging myth
most commonHow to confirm it
Every modern laptop has charging circuitry that stops at full. There is no trickle-charge damage to worry about, and no need to unplug at 100 percent.
The fix
Stop worrying about this specific thing. It is the most repeated piece of laptop advice and it has not been true for many years.
2. High state of charge over long periods
most commonHow to confirm it
This is the real mechanism: lithium cells age faster when held near full, and faster still when warm. A desk machine permanently at 100 percent is the worst ordinary case.
The fix
Use the maker's charge limit, typically 60 or 80 percent. This is the single most effective thing you can do for long-term battery health, and it costs you nothing on a machine that rarely leaves the desk.
3. Heat, which compounds everything
commonHow to confirm it
A machine that runs hot while plugged in, on a soft surface or in a hot room, ages its battery faster than the same machine kept cool.
The fix
Hard surface and airflow. Battery ageing is one more reason cooling maintenance pays off.
4. Deep discharges at the other extreme
commonHow to confirm it
Repeatedly running to zero is also hard on the cells, which is why the advice is a middle band rather than simply staying low.
The fix
Aim to live between roughly 20 and 80 percent where convenient. Perfection is not required; avoiding both extremes most of the time is.
5. Long-term storage at full or empty
occasionalHow to confirm it
A machine put away for months at 100 percent, or at zero, will lose noticeably more capacity than one stored around half.
The fix
Store at roughly 50 percent, somewhere cool, and top it up every few months.
Measure it instead of guessing
The relevant test here is a comparison rather than a curve: run it plugged in and again on battery. A machine that performs the same in both is on a healthy battery and a full-wattage charger, which is the state good charging habits are meant to preserve.
What software cannot tell you here
- We cannot read battery health or cycle count, which the operating system's battery report gives in one command.
- We cannot see whether a charge limit is enabled, which lives in the maker's app or the system settings.
Asked, in people’s own words
- Should I remove my laptop battery when plugged in?
- On the few machines where it is removable, this is no longer recommended: many laptops perform worse without a battery because they cannot draw short bursts of power, and a battery stored badly ages anyway. Use a charge limit instead, which achieves the same goal without the drawbacks.
- What percentage should I keep my laptop battery at?
- Between roughly 20 and 80 percent for daily use, and around 50 percent for long storage. If your machine offers a charge limit at 60 or 80 percent, that setting does the work for you and is the most useful battery feature most people never turn on.
- Does leaving a laptop charging overnight damage it?
- No. It stops charging at full and runs from the mains, so a single night changes nothing. The thing worth changing is not overnight charging but permanent residency at 100 percent over months, which is exactly what a charge limit prevents.